Photoelectric paper cutting control



Aug. 1;,JQ36. F. H. G'ULLIKSEN PHOTOELECTRIC PAPER CUTTING CONTROL FiledFeb. '1, 1932 2 Sheets-Sheet 2 INVENTOR Him H GulZZ/isen.

WITNESSES:

IATTCSRNEY Patented Aug. 11, 1936 UNITED- STATES PATENT OFFICEPHOTOELECTRIC PAPER CUTTING CONTROL Application February 1, 1932, SerialNo. 590,267

1 Claim.

This invention relates to electrical control systems for apparatusoperating on material.

More specifically, this invention relates to electrical control systems,involving thermionic means and light sensitive means, for controllingthe relative positions and relative speeds of certain parts of a machineoperating on a web.

In the art of paper cutting or printing, the operation on the paper orweb of material, when moving from a supply reel past certain rolls tothe cutter, nearly always involves slippage, thus the paper becomesshifted relative to the cutter or other machine. Even when there be noslippage, the hygroscopic characteristics of paper, or temperature orboth, cause a change in its dimension with changes of relative humidityand/or changes in temperature with the result that the cutter will notcut the paper along the desired line. Slippage and the moisture effectmay, of course, occur simultaneously and tend to compensate or tocumulate.

It is an object of this invention to control the operation of apparatusoperating on a web so that the required operation on the web will takeplace at the right point regardless of the slippage of the web or thechange of dimension of the web or both.

Another object of this invention is to control the relative speeds of acutter and the feeding means of a machine operating on a web byphotoelectric control means. I

A further object of this invention is to control the position of the webin a machine operating on a web by photo-e1ectric control means.

Another object of this invention is to control the relative speeds ofcertain parts of a machine operating on a web and the relative positionof these parts by the cooperative action of photoelectric and thermionicmeans.

Other objects and advantages will become apparent from a study of thefollowing specification when considered in conjunction with theaccompanying drawings, in which:

Figure 1 is a diagrammatic showing of the cutter, web-feeding device anddriving means therefor; and I Fig. 2 is a diagrammatic showing of partof the control system for controlling the operation of some of theequipment shown in Fig. 1.

Referring more particularly to Fig. 1 of the drawings, I26 designates aninduction motor, or. any other electric motor, supplied with electricalenergy from the buses'20l, 202 and 203 through the line contactor I29. Acutter 29 is coupled to the motor I26 through the reduction gear I3I.

The motor I26 is also utilized to drivethe web feeding mechanism or roll28, the operation of the web feeding mechanism taking place through amechanical differential, or localizer, and a speed changer both of whichmay be adjusted by a pair 5 of motors I01 and I03, respectively. The webfeeding mechanism 28 is coupled to a shaft I33 through suitablereduction gearing.

Associated with the apparatus for operating on the web is alightsensitive device I! and a 10 source of light 21 mounted in the housing221 provided with the slit 228.

Some of the control equipment appears on Fig.

1 but the main part of the control equipment is shown in Fig. 2 andconsists of a plurality of 15 amplifier tubes I8, I9 and 24 and a'pairof hot cathode tubes 22 and 23.

The theory of operation of the scheme, generally stated, embodies thesynchronizing of a spot I, printed on the paper, with the operation ofsome contact members 30, 3| and 32 designed to rotate with the cutterwhen the cut is right on the spot or at some predetermined distance fromthe spot. When the spot is synchronized the brushes on the contactmembers do not engage the contact segments thereof when the photocellimpulse from the cell I1 is obtained. If however, the spot I is not inproper position with ref erence to the cutter 29, the impulse given tothe photo-cell H by the increase of current flowing 30 therein modifiesthe operation of amplifier tube I9 and this modified operation, becauseof the fact that the contact segments coupled to the cutter are not insynchronism with the spot on the paper or web, causes the hot cathodetube 23 or 22, as the case may be, to break down thereby operatingeither relay I or relay 2. When one of these relays has operated, one ofthe contactors 34 or 35 may be operated to establish a circuit for themotors I01 and I03 (see Fig. 1).

Operation of the motor I01 causes a shift in position between the cutter29 and the web feeding roll 28, whereas the operation of motor I03causes a change in the speed difference between the cutter and the webfeeding roll 28. Since, as here broadly indicated, both motors I01 and II03 are caused to operate, the change in speed relation between thecutter and the web feeding mechanism is in the direction to make thecorrection necessary to perfectly synchronize this spot on the web andthe knife of the cutter. The operation of the motor I01, operating onthe housing I22 of the differential mechanism, causes a shift inposition between the cutter and the web feeding roll 28 in such adirection as to correct for the amount of asynchronous operation betweenthe cutter blade and the spot on the web. After the motor I01 or I03 hasoperated for a short interval of time determined by a timing circuitarrangement described more in detail hereinafter, the correctionnecessary may have been completed and no further synchronizing operationis necessary. v

An important factor in any cutter control application is the mechanicalarrangement of the feed-roll, speed-changing device, and the localizerequipment. In. some cutting applications, the slip of the paper isrelatively small or substantially zero or practically constant so thatwhen the speed ratio between cutter and the feed roll is once adjusted,the entire control can be obtained by means of the localizer adjustment,namely, the positioning of the housing I22 of the difierentialmechanism.

In other applications, the slip varies considerably from time to timedue to changing air moisture and air temperature and a speed ratiochange as well as a localizing change is required in order to getsatisfactory operation. It is, therefore, obvious that for someapplications, the motor I03 may be required to operate whenever the spotI on the web and the cutter 29 are not synchronized and the motor I01operating the mechanical localizer equipment is also required to operateat the same time. However, when such combined operation is notnecessary, switches 204 and 205 may be selectively operated so thateither motor I03 or motor I01 or both may be caused to operate when thespot on the web is not in synchronism with the knife of the cutter.

A better understanding of the invention may be had from a study of thesequence of operation involving a typical synchronizing operation forthe spot on the web and the cutter. In the specific embodiment hereindisclosed, reference characters 5|, 52 and 53 designate the bus bars ofa 60-cycle, three-phase, 440-volt source of alternating current andreference characters 4| and 44 represent the buses of a single-phase,60- cycle, l10-volt circuit. It is to be understood, however, that thespecific frequencies mentioned or voltages of the sources of supply arenot part of this invention and merely disclose one application of thisinvention.

Assuming manually operated controller segments 43, 45, 46 and 41 aremoved to bridge the contact fingers shown in connection with thecontroller segments, a plurality of circuits are thereby established.The transformer 36 is energized from conductors 4| and 42 andtransformer 38 and the light 21 are also energized from the conductors4| and 42. The transformer 38 has a double-wave rectifier 25 connectedin the secondary windings 40 thereof and conductors 13 and 14 areconnected to the direct-current junctions of the rectifier 25. Toprovide for the requisite sensitivity of photo-cell I1, the condensers15 and 11 and the reactor 16, resistor sections 18 and H2 and resistorIII are interconnected with the photo-cell I1 by conductors 19 and 80.The photo-cell I1 is so positioned with reference to the source of light21 that the light coming from source 21 passes through the slot 228 andthrough the material onto the sensitive elements of the photo-cell. Theresistance value of the resistor III as well as the potentiometercircuit involving resistors I I2 and 18 increase the sensitivity of thephoto-cell I1 so that a slight variation in the amount of lighttransmitted through the web will materially increase the current flowingin' been properly heated. To prevent premature the photo-cell circuit.Any change in the amount of current flowing in the photo-cell I1 will,by the conductor 80, increase the negative bias on the grid of theamplifier tube I9 and thus materially decrease the current flowingthrough 5 tube I9.

The transformer 36 is provided with a plurality I of secondaries 26, 2|,20 and 31; the secondary 26 energizes the filament of amplifier tube I8through conductors 10 and 1|; the secondary 2| o energizes the filamentof the amplifier tube I9 through conductors 68 and 69; the secondary 20energizes the filament of the hot cathode tube 23 through conductors 63,65, 66 and 61 and also energizes the filament of the hot cathode tube 225 through conductors 63, 65, I53 and I54; and the secondary 31 energizesthe filament of the amplifier tube 24 through conductors 6|, 62 and 56.It should be noted that the secondary 20 of the transformer 36 isprovided with a tap at its mid- 20 point and a conductor 64 leading tothe resistor I3.' When there is a predetermined change in the currentflowing through resistors 9 and I0, either hot cathode tube 22 or hotcathode tube 23 will be caused to break down in a manner 25 morespecifically pointed out hereinafter.

A double-wave rectifier 48 is interconnected with the buses 5|, 52 and53 by the controller segments 45, 46 and 41 thereby supplying theconductors 49 and 50 with a direct current potential. 30 Assumingconductors 49 and 50 are energized,

a circuit is established from conductor 50 through resistor I5, resistorI3 in parallel circuit relation filament of tube 24 and the resistorsections I3 and I5 occurs at substantially the same instant.

it is desirable that no operation of the hot cathode tubes can takeplace before the filaments have operation of any of the controlequipment, the condenser 59 and the resistor 58 are interconnected withthe resistor sections I5, I3 and 60 and the grid of the tube 24 in sucha manner that a negative bias is placed on the tube 24 for asubstantially predetermined interval of time and no current can,therefore, flow from the conductor 55 to the conductor 56 prior to theexpiration of such predetermined interval of time.

After the lapse of the predetermined interval of time mentioned, theeifect of the resistor 58 and the condenser 59 becomes negligible and anoperating circuit for the relay 4 is established from the energizedconductor 50 through the actuating coil of the relay 4 through conductor55 55, the plate and filament of the amplifier tube 24, conductor 56,resistors I3- and 60 connected in parallel circuit relation andconductor 51 to the energized conductor 49.

For the complete operation of this system, it 60 must, of course, beassumed that the switch I21 has been closed to energize the actuatingcoil I 28 of the line contactor I29 thereby energizing the motor I26from the conductors 20I, 202 and 203. Operation of the motor I26 drivesthe cut- 65 ter 29 and the contact members 30, 3| and 32 through thereduction gear- I3I and this motor also drives the web feeding roll 28through shaft I23, bevel gears I24 and I25 of the mechanical localizer225, the speed-changing device 226 and 70 the shaft I33 to the feedingroll 28 by means of the reduction gearing shown. The material I32 is fedfrom a supply reel I34.and passes over the idling and tension adjustingrollers I35 and I" of the feeding roll 28 with which it is made toerr--7 gage by the spring actuated idler roll I31. As will be observed,any movement of the cam I08 will operate the spring biased levers H1 andH8 pivoted at H5 and H8 in such a direction that the cone-shapedtwo-part pulleys H3 and H4 will change the speed of the roll 28 relativeto the speed of the cutter 29. As long as the housing I 22 remainsfixed, the relative position of the feed roll 28 and the cutter 29remains fixed and for any given position of the cam I08, the relativespeeds of the cutter and feeding device remains constant. It is obviousthat the paper or other web material after having been threaded throughthe machine may not be in proper position, that is, the line on whichthe paper is to be cut may not.

be at the desired position. To efiect the proper positioning of theknife of the cutter with reference to the web, switch 205 is closed andcontroller C is operated in one or the other direction to bridge thecontact fingers shown therewith, depending on the direction -in'which itis desired to move the cutter with reference to the web. After thecutter has been properly positioned, the controller C is againpositioned as shown and switches 205 and 204 are closed, if both a speedchanging adjustment and a localizer adjustment is desired during thenormal operation of the paper cutter. If but one of the adjustments isdesired, either switch 205 or switch 204 is closed depending upon whichadjustment is desired. More often, both switches 204 and 205 are closedbecause, due to the hygroscopic characteristics of paper, the slippagemay change from time to time and the rate of change may vary so that notonly a change in the speed relation between the cutter 29 and the webfeeding roll 28 is necessary but also a repositioning of the cutter 29with reference to the web and, in consequence, roll 28 is necessary.

The web is provided with indicia on the edge thereof consisting of ablack or apaque mark I about a quarter of an inch in width and one-halfof an inch in depth, just sufficient to periodically cut ofi a largepercentage of the light falling on the photo-cell I1 from the source oflight 21. The specific dimensions of the printed mark are not materialto this invention. It is suflicient that some indicia be placed on theweb at the points it is desired the web is to be cut or at somepredetermined position with reference to the desired cut so that theamount of light transmitted from the source of light to the photo-cellis periodically modified.

If the apparatus is in, normal operation and the adjustment of the webwith reference to the cutter as well as the speed of the cutter withreference to the web feeding device 28 has been properly adjusted andthat, due to slippage or the change in dimensions of the web due to itshygroscopic character or due to the changes in temperature surroundingthe web, the indicia I are not in the desired position with reference tothe cutter, the contact segments 3I or 32 will be in such a positionthat motors I03 and I01 may be caused to operate.

Each time the printed mark I passes between the source of light 21 andthe photo-cell I1, the amount of curent passing through the photo-cellis materially decreased and the grid voltage of the amplifier tube I9 ischanged so that the current flowing from the plate of the tube I 9 tothe cathode is increased, the current passing from the energizedconductor 50 through conductor 8|, the plate and filament of the tubeI9, conductor 82, contact ring 30 (see Fig. 1), contact segment 3|,

conductor 83 to the junction G, resistor I0 and conductor 85 to theenergized conductor 49. The change in current through resistor I0changes the bias on the grid of tube 23, because 'the grid of the hotcathode tube is connected to the junction G through the resistor 84.

The change of the bias on the hot cathode tube 23 causes this tube tobreak. down and a circuit is thereby established from the energizedconductor 50 through conductor 86, contact members 81 of the relay 4(now closed), contact members 88 of the relay 3, resistor 33, contactmem-- bers 89 of the relay I, actuating coil 90 of the control relay 2,the hot cathode tube 23, conductors B6 and 61 through the secondarywinding 20 of the transformer 36, conductor 84 to a portion of aresistor I3 and conductor 51 to the energized conductor 49. Operation ofthe control relay 2 causes the opening of the contact members I5Ithereby preventing the operation of the control relay I even though thehot cathode tube 22 may forsome cause break down. A circuit is alsoestablished from the energized conductor 42 through conductor 9|,contact members 92 of relay 2, conductor 93, the actuating coil of theline contactor 35 and conductor 95 to the energized conductor 4|.Operation of the line contactor 35 establishes a circuit between thebuses 96 and I05 leading to a suitable source of direct current power,the circuit being through the conductors 91, 98 and 99, contact membersI00 of the relay 35, conductor IOI, series field windings I 02 and I09and the respective armatures of the motors I03 and I01, switches 204 and205 and conductor 304 to the energized conductor I 05.

'Themotors I03 and I01 will, therefore, operate to change the speedrelation between the web feeding roll 28 and the cutter 29 and also therelative position of the cutter with reference to the feed roll 28.

Since the plate voltage of the tube 23 is supplied from a source ofdirect current power, the tube will remain broken down even after thegrid of the tube is again made negative due to a decrease in the platecurrent of the tube I9. The operation of the motors I03 and I81 will,therefore, continue until stopped by some other means.

It will be noted that the operation of the control relay 2 also closedthe contact members I43 thereby establishing a circuit from theenergized conductor 50 through the resistors I4, and I4 and I6 connectedin parallel circuit relation, conductors I40 and I42, contact membersI43 of relay 2, conductors I44, I45 and 85 to the energized conductor49. The current flowing through they resistor I6 and the resistorsections I 4' and I4 changes the potential of the grid of the amplifiertube I8 so that the current from the plate to the filament of tube I8 ismaterially increased. However, to prevent the immediate change incurrent through the tube I8, the potentiometer circuit, shown at theresistors I4 and I6, is utilized and interconnected with the condenser 6and the resistor 5 by the conductor 12. After the lapse of asubstantially predetermined interval of time, the current intheamplifier-tube I8 will increase by an amount suflicient to operate thecontrol relay 3. The circuit for the control relay 3 may be traced fromthe energized conductor 50, the actuating coil of the control relay 3,conductor I 39, the plate and filament of the amplifier tube I8,conductor 1I, resistor I4 and I6, conductors I40 and I42, contactmembers I43 of the relay 2, and conductors I44, I45 and 85 to theenergized conductor 49. Since the control relay 3 is sum-- cientlyenergized to operate, contact members 88 are moved to open circuitposition thereby deenergizing the actuating coil of the control relay 2.When the control relay 2 is deenergized, the circuit for the linecontactor 35 is interrupted and the motors I03 and I01 are caused tostop. Since the contact members I43 are also open, the bias on the gridof the tube I8 is also removed and control relay 3 is deenergized andcontact members 88 are again closed. Since the contact members 88, I5Iand 89 are again in circuit closing positions whereas the contactmembers 81 remain in circuit closing position, the sequence of operationmay be repeated if and when the indicia I have become displaced withreference to the cutter.

For the preceding discussion it was assumed the indicia were displacedin a given direction with reference to the cutter, say behind thecutter. If the opaque mark be ahead of the cutter, the sequence ofoperation is much like that heretofore discussed except that the contactsegment 32 is now brought in cooperative relation with the brushconnected to the conductor I55 just when the impulse from the photo-cellI1 is received. Such being the case, a circuit is established from theenergized conductor 50 through conductor 8|, the plate and filament ofthe amplifier tube I9, conductor 82, contact ring 30, contact segment32, conductor I55, and resistor 9 to the energized conductor 49. Thechange in current in resistor 9 changes the bias on the grid of tube 22,when the circuit is completed through the contact ring 30 and thecontact segment 32. To prevent excessive current through the grid of thehot cathode tube 22, resistor I56 is interconnected with the grid andthe conductor I55.

The change of bias on the grid of the hot cathode tube 22 causes theoperation of the control relay I. The circuitfor control relay I may betraced from the energized conductor 50 through conductor 86, contactmembers 81 and operation of Lthe control relay 2. Closing of the contactmembers I58 establishes a circuit from the energized conductor 42through conductors 9| and I51, contact members I58 of the relay I,conductor I59, the actuating coil of the line contactor 34 and conductorto the energized conductor M. The line contactor 34 connects the motorsI03 and I01 for reverse operation to the source of supply 96 and I05.The circuits for the motors may be traced from the energized conductor98 through conductors 91 and 98, contact members I60 of the contactor34, conductors I6I and I62, series field .windings I63 and I64 and thearmatures of the respective motors I01 and I03, switches 205 and 204 andconductor 304 to the energized conductor I05. Since the series fieldwindings I63 and I64 are energized, the localizer equipment 225 as wellas the speed changing device 226 are both operated to such a positionthat the indicia I is properly positioned with reference.

to the cutter 29.

Closing of the contact members 243 of the relay I completes the circuitthrough the resistors I4, I4 and I6 thereby efiecting the operation ofthe amplifier tube I8 in a manner similar to that heretofore discussed.It is, therefore, obvious that motors I03 and I01 will operate for ashort interval of time making the necessary corrections and are thendeenergized by the controlling action of the amplifier tube I8.

Attention is called to the fact that the localizer equipment 225 has thehousing of the difierential rigidly connected to the worm wheel I2Iwhich is operated by the worm I20 driven by the shaft I I9 coupled tothe motor I01. This sort of an arrangement provides an irreversiblemechanism and holds the housing I22 in fixedposition during normaloperation of the paper cutter. The condensers II and I2 interconnectwith the resistor sections 1, 8, 9 and I0 and are for the purpose ofcontrolling the time constants of the hot cathode tubes 22 and 23,respectively.

It is, of course, understood that the control equipment as shown doesnot necessitate a source of light so disposed with reference to thephotocell that the amount of light received by the photo-cell iscontrolled by the amount of light transmitted through the material.Obviously, the photo-cell may be so positioned with reference to thefeeding roll 28 or the idling and tension adjusting rollers I35 and I36that light falling on these rollers may be reflected on to thephoto-cell I1. Any modification of the amount of light reflected due toindicia placed on the web will effoot the same kind of a control as thatherein described.

Furthermore, instead of positioning the photocell I1 as shown in Fig. 1,the light and photocell may be so pcsitioned that a screen actuated byan idler roll moving with varying positions of the slack loop in thematerial will cause the operation of the control equipment.

While the invention shown in the accompanying drawings and described inthe foregoing specification represents one specific embodiment thereof,it is readily appreciated that the circuit arrangement and the controlequipment utilized therewith may be modified to still fall within thespirit and scope of this invention. It is to be understood that thisinvention is only to be limited by the interpretation of the appendedclaim, as required by the prior art.

I claim as my invention:

' In a tubing machine for making tubular sections of equal length fromelongated sheets of paper previously printed with marks at definiteplaces, power driven draw rolls to pull the web through said machine, apower driven rotary cutter for severing the web into equal sections, anindividually adjustable, variable speed transmission to vary the setspeed of said draw rolls with respect to the speed of said rotary meansto compensate for slippage of said draw rolls with respect to said web,a pilot motor for changing the setting of said variable speedtransmission,

two circuits for controlling said motor, a rotatable 6 switchalternately closing said circuits, a photo tum for controlling theamount of current flowing through said circuits and a source of lightco-operating with said marks on said web for controlling said motor bysaid photo tube.

FINN H. GUILIKSEN.

